The present invention is related to miter saws including compound miter saws, and in particular, to a miter saw having a workpiece supporting fence which has adjustable longitudinal movement and automatically adjustable transverse movement for saw blade as the blade is rotated to various miter positions.
The above mentioned patents disclose a number of improvements to compound miter saws. One of the improvements includes a workpiece supporting fence that is maintained in alignment with a turntable saw blade slot, as the saw blade and the turntable, with its included saw blade slot, are rotated to make desired miter cuts. Thus, as the saw blade and turntable are rotated, the workpiece supporting fence moves from side-to-side in order to keep a workpiece supporting fence cutout in line with the blade. If the fence were not so moved, it would have to be cutout sufficiently so as to not interfere with the blade at its various miter angles. This would require the use of more material, if the same fence strength were to be kept, thus making the saw more expensive to produce.
The first above-mentioned U.S. Pat. No. 5,063,805 is directed to an 81/4" saw wherein the workpiece supporting fence is permanently positioned behind the centerline of the turntable. The disclosed means for automatically moving the workpiece supporting fence as set forth in that patent works for its intended use. However, when the workpiece supporting fence is permanently positioned behind the center line of the turntable on the 81/4" saw, the fence is always moved as the turntable is rotated. Thus, it will not work as well on a 10" miter saw in which the fence is desirably moved between a rearward position, behind the centerline of the turntable where the fence needs the side-to-side adjustment, and a forward position, on the centerline of the turntable, where the side-to-side adjustment is not needed.
Both U.S. Pat. No. 4,934,233 and 5,043,348 are directed to a 10" compound miter saw. In the construction shown in both these patents, there are some problems in moving the fence when it is in its rearward position. These problems include maintaining proper clearance to the saw blade, the strength of the part that moves the fence and its ability to handle abuse, and the added complexity in the design of mating parts. Further, in order to move the fence between a forward and a rearward position, the fence has to be totally removed from the table and re-affixed to the table in its desired position.
The present invention provides an improved workpiece supporting fence with adjustable longitudinal movement and automatically adjustable transverse movement relative to the saw blade which operates in a manner not heretofore contemplated by the prior art, as will be discussed in detail below.